The experiments proposed for the coming year will study the effects of fatty acids and bile acids on intestinal transit time. The studies will be performed in healthy volunteers with a jejunal perfusion technique which uses dye dilution curves for transit time determinations. To test whether the observed changes are due to a local effect of these agents or mediated by humoral or neural mechanisms we will try to develop a method which allows the measurement of intestinal transit time in a segment of intestine separate from that directly exposed to the effective agents. Since we observed that hydroxy fatty acids inhibit the absorption of other solutes we will examine postprandial contents of patients with bacterial overgrowth for presence of hydroxy stearic acid should these patients become available.